Screening and fractional purification of antimicrobial compound of Streptomyces sp. MAB 18 isolated from coastal sediment of Nagapattinam, south-east coast of India

A total of 42 strains of actinobacteria were isolated from five different stations. Out of these 42 isolates, the suspected 10 actinobacterial strains were screened and inoculated for purification, and based on the preliminary screening results, MAB18 was taken to investigate the extraction evaluation of its antimicrobial property. Then it was tested against bacterial and fungal pathogens. The highest zone of inhibition was observed against E. coli (8.2 +/- 0.8mm), P. aeroginosa (10.4 +/- 0.6 mm), Vibrio harveyi (7.2 +/- 0.8mm), S. typhi (10.6 +/--0.4 mm) for bacteria and A. niger (11.2 +/- 0.8 mm), and A. flavus (9.8 +/- 0.2 mm) C. albicans (10.4 +/- 0.6mm), and Penicillium sp. (7.2 +/- 0.8mm), for fungi, whereas it was 21.4 +/- 0.6 and 20.4 +/- 0.6 mm for the standard ampicillin and nystatin. The antibiotic producing actinomycetes may be tapped as one of the India's potential source of novel antibiotics to be used against both bacterial and fungal pathogenic organisms.